This invention relates to an excavating tooth assembly and more particularly, to an assembly featuring a novel lock arrangement for removably securing a point on an adapter.
Traditional excavating tooth locking devices depend on enclosure within centrally located apertures in the tooth components for development of dislodgement resistive forces. Until the development of the HELILOK.RTM. twist-on point (U.S. Pat. No. 4,335,532) virtually all commercial teeth used a combination of a rigid lock such as a pin and a resilient keeper such as a plug. Historically, the rubber plug operated through the lock to tighten the point on the nose of the adapter and these same tightening forces maintained the engagement of the plug with the locking pin to resist pin ejection. The drawback in this approach was that resistance to pin dislodgement diminished as the point/nose fit loosened through service--with resultant reduction in tooth tightening forces.
The above-mentioned '532 patent did not use centrally located apertures for containment but rather a U-shaped lock straddling the adapter and engaging rearwardly extending tongues on the point. This realized a significant increase in strength over preceding teeth. Relative to the '532 patent I have invented a new locking system therefor which offers several improvements and advantages over the U-shaped fastener.
The invention involves an externally mounted elongated shaped lock which provides a point tightening force through cooperative engagement with two vertically disposed ears connected by a ledge on one side of the adapter nose and with the lug on one ear of the point through spring-like deformation from its free shape. This lock is maintained in place by engagement with a retractable plug centrally located in the side of the adapter nose. The adapter nose ears project from the side of the nose a distance approximately equal to the thickness of the elongated lock. The connecting ledge provides a guide function when the lock is driven into place and then a secondary bearing function in operation of the tooth assembly to prevent overstressing of the lock. This ledge projects from the side of the nose a distance of approximately half the thickness of the elongated lock. The invention provides the following advantages and improvements:
1. Extended lock life through a unique stabilized wedge action; PA1 2. Reduction of effort for lock removal; PA1 3. Reduced cost; PA1 4. No requirement for a dedicated lock removal tool; and PA1 5. Increase in adapter nose life.